Printing telegraph apparatus



H. L. KRUM 2,233,667

PRINTING TELEGRAPH APPARATUS Filed July 19, 1937 4 sheets-Sheet 1 March 4, 1941.

March 4, 1941. H, KRUM 2,233,667

PRINTING TELEGRAPH APPARATUS Filed July 19, 1937 4 Sheets-Sheet 2 INVENTOR HOWARD L. KRUM i E E l 79 bzgl-l 82 AATTOR EY FIG. 5

March 4, 1941. H. L KRUM 2,233,667

PRINTING TELEGRAPH APPARATUS Filed July 19, 1937 4 sheets-sheet 3 'mu L IO 25e 9 FIG.

. INVENTOR HOWARD L -KRUM ATTOR Y F l G. l2

FIG. 9

March 4, 1941.

H. L. KRUM 2,233,667

PRINTING TELEGRAPH APPARATUS Filed July 19, 1957 4 Sheets-Sheet 4 L--zoe 335 355 353 +Mw.. FIG. I9

INVENTOR 362 HOWARD L. KRUM ATTORNEY Patented Mar. 4, 1.941

PRINTING TELEGRAPH APPARATUS Howard L. Krom, Kenilworth, Ill., assgnor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application July 19, 1937, Serial No. 154,377

16 Claims.

This invention relates to printing telegraph systems and apparatus and more particularly to two channel systems of telegraphic transmission for controlling telegraphic recorders, and to recorders operative on such a system.

An object of the invention is the provision of a relatively simple telegraph system by utilizing two transmission channels for character selection and printing.

Another object of the invention is to eifect character selection in a printing telegraph receiver, in variable steps, in accordance with the Variable number of impulses applied to the signal channel.

In accordance with one embodiment of the present invention, the printing apparatus operates on a two channel or wire system in which one line wire is connected through one ratchetcontrolled magnet to a winding of a printing magnet, and the other line wire is connected through a second ratchet-controlling magnet to the same winding of the printing magnet. Since the printing magnet is marginal in operation, it responds only to curr-ent applied simultaneously on both line wires, and character printing is effected only when both windings of the ratchetcontrolling magnets and the winding of the printing magnet are energized. Each character signal consists of three parts; namely, a plurality of stepping impulses, a prolonged printing impulse, and a plurality of restoration impulses, all of which occur concurrently on both line wires. For example, the stepping impulses occurring on one line wire control the stepping of a type wheel one thirty-sixth of a revolution per impulse, and the stepping impulses occurring on the second line wire control the stepping of the type wheel one-sixth of a revolution per impulse. these positioning impulses exist on both line wires concurrently or exist during the same signal periodbut not simultaneously, the impulses on one line Wire are staggered with respect to the impulses on the other line, so as not to energize the print magnet prematurely. The m-aximum number of impulses on either line necessary to step the type wheel from its zero or starting position to the last one of its thirty-six positions is ve. The second part of the character signal consists of a prolonged impulse occurring on both lines simultaneously and functions to operate the printing magnet which is designed to operate in response to greater current than the selecting or ratchet-controlling magnets, hence the requirement that the current on both lines simultaneouslybe necessary to oper- Although ate the printing magnet. The third part of the signal consists of a series of impulses, occurring on both line wires concurrently, six on each wire, and staggered similarly to the positioning impulses, so as to affect only the ratchet-control- 5 ling magnets and not the printing magnet, the function of which vis to effect the restoration of the type wheel to its initial or starting position. Thus, responsive to the restoration impulses is a restoration mechanism which prevents said im- 10 pulses from rotating the type wheel further than to its rero orstarting position.

One modiied form of the present invention consists in substituting for the neutral selecting or ratchet-controlling magnets, rotary-arma- 15 ture types of magnet, and arranging the axes of the armatures of the two character selecting magnets in coaxial alignment with the cent-er of the type wheel. The magnets are then adapted to control through differential or planetary gear- 20 ing the selective positionment of the type wheel. In this form o-f the invention the printing function is likewise performed by means of a rotaryarmature type magnet. A particular feature of this type of printer is the association with each 25 rotary-armature of a multi-toothed cam, with teeth corresponding in number to the pairs of diametrically opposed armature poles, the feature residing in the fact that the armature is rotated in part by the magnet and in part by the -spring actuated detent cooperating with the multi-toothed cam, the action of each to effect rotation of the armature occurring alternatively.

The above and other objects of the invention will be apparent from the following description when taken in conjunction with the accompanying drawings, wherein like reference characters designate similar parts throughout the several views, in which,

Fig. 1 is a front elevational View of the printer 4 according to the preferred form of the invention;

Fig. 2 is a rear elevational view of the form of printer shown in Fig. 1;

Fig. 3 is a fragmentary sectional View taken on line 3-3 of Fig. 1;

Fig. 4 is a graphic representation of the form of signal employed by the present invention;

Fig. 5 is a rear elevational View of a modified form of the invention;

Fig. 6 is a fragmentary rear view of a further form of the invention;

Fig. 7 is a fragmentary perspective View of a spring return means for the type wheel employed with the printer shown in Fig. 6;

Fig. 8 is a front elevational View, with parts broken away, of the rotary-armature type of printer embodying the principles of the present invention;

Fig. 9 is a sectional View taken on line 9-9 of Fig. 8;

Fig. 10 is a sectional View taken on line I-I of Fig. 8;

Fig. 11 is a partial rear elevational View of the printer shown in Fig. 8;

Fig. 12 is a schematic wiring diagram of the circuit for operating the printer shown in Fig. y8;

Fig. 13 is a partial plan view of the keyboard transmitter employed with the preferred form of the present invention;

Fig. 14 is a sectional view taken on line Irl- I4 of Fig. 13; i

Fig. 15 is a View showing the series of contact cams;

Fig. 16 is a schematic electrical circuit embodying the transmitter shown in Fig. 13 and the receiving printers sho-wn in Figs. 2, 5, 6, and/or 8;

Fig. 17 is a cross-sectional view of a dial type transmitter;

Fig. 18 is a top View of the transmitter shown in Fig. 17, and

Fig. 19 is a schematic electrical circuit embodying the transmitter shown in Fig. 17 and the receiving printers of the present invention embodying the type wheel return mechanism shown in Fig. 7.

Having reference to Figs. 1 to 4, the framework o-f the printing apparatus according to the preferred form of the present invention ycomprises a base plate II supporting a mounting plate I2 attached thereto through the instrumentality of a bar I3 by means of screws I4. A U-shaped bracket l is fixed to the mounting plate I2, and together with the mounting plate I2 provides a journal bearing for a type wheel shaft I6, as seen in Fig. 3. Fixed toshaft I6, to the right of mounting plate I2, as viewed in Fig. 3, is atype wheel I1 which has associated therewith a star wheel I8. Between the web of bracket I5 and mounting plate I2, shaft I5 carries thereon a sleeve I9 and a pinion gear 2|, the latter pinion Ibeing xed to the shaft I6. Integral with sleeve I9 is a ratchet wheel 22l in which is journaled a shaft 23 which carries Xed thereon, planetary gears 24 and 25 disposed one on each side of the ratchet wheel 22. The

planetary gear 25 meshes with the pinion 2 I, and.

planetary gear 24 meshes with a pinion 26 which is integral with a sleeve 21 loosely mounted on the sleeve I9. A ratchet wheel 28 is also integral with the sleeve 21. Fixed to shaft I6 to the left of mounting bracket I5 (as viewed in Fig. 3) is a collar 29 which carries a spring post 3| (as viewed in Fig. 2) to which is connected one end of a coiled spring 32, the other end of which is connected to a pin 33 carried on a blocking segment 34 loosely mounted on shaft I6, the function of which will hereinafter appear.

As viewed-in Fig. 2, ratchet wheel 22 has associated therewith a pawl 35 carried at the extremity of a pawl operating lever 36 which isV associated with an armature 31 of an electromagnet 38. Electromagnet 38 is carried on a Abracket 39 which in turn is mounted on a bracket 4I secured to the mounting plate I2. The armature 31 is pivotally supported at 42 to bracket 39 and isl lbiased in a clockwise direction by a spring 43..v Spring 43. thus normally, when magnet 33 is deenergized, maintains pawl operating lever 36 against stop portion 44 of a stop bracket 45.

Ratchet Wheel 28 has associated therewith a pawl 46 carried at the extremity of a pawl operating lever 41 which is integral with the armature 48 of an electromagnet 49. Electromagnet 49 is carried on a bracket 5I which is supported on a bracket 52 secured to mounting plate I2. Armature 48 is pivotally supported at 53 on ibracket 5I and is biased in counterclockwise direction by a spring 54, which normally maintains pawl operating lever 41 against an adjustable stop 60.

A printing magnet 55 is supported through angle brackets 56 and 51 to a plate 58 which in turn is carried by an angle bracket 59 secured to mounting plate I2. In the present embodiment, magnet 55 is provided with two windings, one of which controls an armature 6I pivotally mounted at 62 to the plate 58. Integral with armature 6I is a printing control lever 63 near the extremity of which is secured an extension- The printing magnet 55 is also provided withv a second winding which controls an armature 1I pivoted at 'I2 to plate 58.A Armaturels 6I and 1I are biased out of engagement with their pole faces by a common spring 13. Armature 'II is provided, integral therewith, with an extension 14 which is so conformed as. to avoid the pawl operating arm 41, and which terminates at its extremity in a hook portion 'l5 which cooperates with a plurality of pins 16 carried on the ratchet wheel 22.

Pawl operating lever 41 is provided with a vertically extending arm 11v which terminates at its upper extremity in a laterally directed portion 18. Portion 18 cooperates with the segment 34 during the performance of the restoration function as will presently appear.

In Fig. 4 is shown a diagrammatic representation of the'type of,v signals received over the two line wires for effecting the selective control and operation of the printer shown in Figs. 1, 2, and.

3. As previously indicated, each character sig.-

nal consists of'three parts namely, the selectingv noted thatv the selecting impulses 83 received over on'e line wire are staggered withA respectto impulses 84 received over. the secondline wire, it being understood that the. number of impulses 83 or 84 vary with the. character received. It-

Will also be observed thatthe printing impulses 8l impressed on each line wire occur simultaneously and are .prolonged in nature. Following the printing impulses are thesrestoration impulses: 85 andV 86V which are always, according to the present invention, sixY in numbery and are staggered las indicated.

Impulses183 arel impressed on electromagnet 3,8,v and as.. eachv impulse-is received, magnet 3BL becomes energized and causes its armature'31to rotate in a :counter-clockwise direction against the action of spring 43, thus rotating the pawl operating lever 3'! counterclockwise to raise pawl 35 to engage the next preceding tooth on the periphery of ratchet 22 preparatory to eiecting rotation of said ratchet. Then upon deenergization of magnet 38 at the termination of said impulse, armature 31 and lever 36 are actuated in a clockwise direction by the spring 43 so that paWl 35 rotates the ratchet 22 through one angular step. This movement of .ratchet 22 causes the planetary gears 24 and '25' to be lcarried lclockwise and since, during this movement the ratchet 28 is prevented from rotating, the gear 24 will be caused to rotate in a clockwise direction thus imparting 'the same movement to the Icompanion planetary gear 25. This movement of planetary gear 25 causes pinion 2|, and hence type wheel I1 and star 'wheel I8, to rotate in a counterclockwise direction as viewed in Fig. 2 (or a clockwise direction as Viewed'in Fig. l). By properly proportioning the4 gears involved in this gear chain, the type Wheel II is moved one angular Isteprepresentative of a single character space on the periphery of the type Wheel for each actuation of pawl 35 bymagnet 38.

When a character selecting impulse 84 is received over the second line Wire, it causes the energization of magnet 49 which, upon energization, attracts its armature 48 to impart clockwise rotation to the pawl operating lever 41 against the action of its spring 54 sufficiently to permit pawl 46 to engage the next preceding tooth on the ratchet wheel 28. mination of said selecting impulse, magnet 49 becomes deenergized and spring 54 acts to rotate armature 48 and lever* 41 countenclockwise, thus actuating pawl 46 upwardly to effect the counterclockwise rotation of ratchet wheel 28 one angular step. Since ratchet Wheel 22 is at this time held against rotation by its pawl 35, the counterclockwise rotation of ratchet wheel 28 effects, through gear 26 and planetary gears 24 and 25 counterclockvvise rotation of pinion 2! and type wheel I 1, as` viewed in Fig. 2. However, instead of rotating the type Wheel only one angular step representative of a single character space, type wheel I1 is rotated six angular steps or through the span of six character spaces of the periphery of the type Wheel I1.

As previously mentioned, character selecting impulses are received over both line wires concurrently except that the impulses on one Wire are staggered With respect to the other, and the number of impulses received over each line Wire is determined by the character to be selected. Rememb-ering that the type wheel is restored to an initial or starting position prior to the selection and printing of each character, it will be assumed that the iifth character on the type wheel counting from the initial or starting position is to be selected. In this event, live irnpulses 83 will be received over the iirst line Wire (and none over the second line wire) thus energizing magnet 38 ve times and rotating ratchet 22 through the angular distance of live teeth to effect the rotation ofthe type wheel I1 correspondingly to present the fth character on the type wheel (counting from the initial or starting position) to the printing point. Now, in the event that it is desired to print the eleventh character on the type wheel counting from the initial or starting position, ve impulses 83 will be received over the first line Wire to actuate Then, upon termagnet 38 and to rotate ratchet 22 five angular steps, and hence type Wheel I1 five character spaces; and one selecting impulse 84 Will be receivedover the second line Wire to energize magnet 49 to operate lever 41 to effect the rotation of ratchet 28 one angular step, in a manner previously described, to cause the rotation of type wheel I1, in a single movement, six character spaces which, when added to the five character space movement resulting from the operation of magnet 38, will have caused the type wheel to be moved through eleven character spaces, thus presenting the eleventh character (counting from the starting position of the type wheel) to the printing point. It is thus seen that time has been saved in selecting the eleventh character on a type Wheel by operating magnet 38 only five times and magnet 49 only once, instead of operating magnet 38 eleven times. Likewise, if magnet 49 is operated twice and magnet 38 is operated five times, the seventeenth character will be presented to the printing point. The latter selection will have been achieved through the transmission of only seven impulses, instead of seventeen impulses, thus emphasizing the decided saving in line time. To select the thirty-fifth or last character on a type wheel (the thirty-sixth or zero position being the blank position of the type Wheel) only five impulses 83 need be transmitted to operate magnet 38 ve times, and iive impulses 84 need only be transmitted to operate the magnet 49 five times. Thus, in all, ten impulses have been transmitted instead of thirtyive.

After the receipt of the character selecting impulses 83 and 84, the selection of the character to be printed from the type wheel has been determined, and following the receipt of these selecting impulses 83-and 84 a prolonged printing impulse 8I is received over both line wires simultaneously, thus energizing the print magnet 55, causing armature 6I thereof to be attracted and printing arm 63 to be actuated in a counterclockwise direction against the action of spring 13 to impart, through portion 64, upward movement to plunger 65, which through lateral portion 61 imparts counterclockwise movement (as viewed in Fig. l) to printing hammer 68, thus throwing the pallet portion of the printing arm 68 against the type wheel I1. At the same time the knife-edge of portion 61 cooperates withA the star wheel I8 to prevent movement of the type wheel I1 during the performance of the printing function. i

The tape 81 is directed in tape guide 88 through the printing area. Engaging tape 81 through a slot (not shown) in the tape guide 88 is a tape spacing roller 89 which is provided, as is common practice, with a knurled periphery and which, to eiect movement of the tape, cooperates With a pressure roller 9| carried on a lever 92 which is spring biased in a counterclockwise direction (as viewed in Fig.` 1) by a spring 93. Roller 89 is mounted on a shaft 94 (Fig. 2) to which is also fixed a spacing ratchet 95. Cooperating with spacing ratchet 95 is a pawl 96 which is carried at the extremity of the printing lever 93. Thus, upon each operation of lever (53 in response to the printing impulse 8l, the pawl 96 is reciprocated thereby engaging the next tooth on the ratchet 95 and upon a downward movement of pawl 96, ratchet 95 is rotated one angular step in a clockwise direction (as View in Fig. 2) thus causing roller 89 to be rotated one angular step in acounterclockwise direction .(as

viewed in Fig. l). A detent spring '91 is provided to prevent back spacing of the ratchet wheel 95 during the performance of the spacing operation. Associated with the type wheel I1, as viewed in Fig. 1, is an inking roller 88 carried on a lever 89 biased by a spring |00. v

As previously indicated, the third part of each character signal comprises a plurality of impulses over each line wire, suici'ent in number to insure the stepping of the type wheel forward (in the saine direction as for character selection) to its starting or Zero position.Y Since sixV impulses over each line wire are sufficient to rotate the type wheel a complete revolution, this number of impulses on each line has been chosen to effect restoration. Of course, the Y extent to which it is necessary to rotate the type wheel to its zero position after the selection of a character varies with the character selected. Therefore, it is necessary to provide mechanism to prevent rotation of the type wheel farther than to its Zero position., To achieve this result in connection with the six-step magnet 49, the segment 34 and arm 11 are provided, and in connection with the one-step magnet 38, the pins 16 and arm 14 are provided.

The magnets 38, 49, and 55 are connected in the manner shown in Fig. 16 wherein the magnet 38 is included in one line wire 3|4 and the magnet 49 is included in the other line wire 3 l 5, magnet 55 being connected to both line wires so that impulses received over line wire 3I4 will pass through magnet 38 thence through magnet 55 to ground. In the form of the invention shown in Fig. 2, the magnet 55 is provided with acter (and controls armature 6i so that the impulses received over only one of the line wires will not energize the marginal winding of the magnet. On the other hand, it requires the total current on the two wires to effect the energization of said marginal winding of magnet 55. Magnet 55 is also provided with a second winding which responds to the selecting and restoration impulses over either wire to cause the operation of armature 1I.

Now, when the restoration impulses are received over line wire 384, they will pass through magnet 38 and also the second mentioned winding of magnet 55. The eiect of restoration impulses 35 on magnet 38 will be to operate arm 36 and pawl 35 to cause the clockwise rotation of ratchet wheel 22. However, since these restoration impulses also pass through the second mentioned winding of magnet 55, armature 1| is operated to rotate lever 14 clockwise to bringy hook portion 15 into the path of pins 16. Thus, pawl 35 will continuato actuate ratchet wheel 2-2, in response to the restoration impulses 85, only until one of the pins 16 is interceptedY by the hook portion 15 after which the remaining restoration impulses 05, if any, will have no effeet; During the character selecting operation, the actuation or arm 14, and hence hool; portion 15, in response to impulses 83 and 84, will have no arresting effect on the ratchet wheel 22, for the reason that the maximum distance thatl ratchet 22 may be rotated during a ycharacter selecting cycle is lve steps, which is less than the number of steps between successive pins 16. l

Similarly, the restoration impulses 86 receivedA over line wire SI5 will pass throughmagnet- 49 and said second windingof magnet 55, The feet of staggering impulsan-andes is to mam:

einladen? extending portion 18. Thus, as lever 41 is oscillated, the portion: 18 is reciprocated vertically. Portion 18 is thus free to reciprocate vertically until .the segment `34 Ais presented'in its path, whereupon oscillation of lever 41 is prevented.

In this manner, typev Wheel I1, during the restoy ration operation, can be moved in six-step or sixcharacter-'space intervalsuntil segment 34 is pref sented beneath the portion 18, after which the remaining restoration impulses, if any, will have no eiect upon lever 41.` The mechanism is so designed that when a pin 16 is intercepted by vhook portion 15, and the portion 18 is intercepted simultaneously therewith by segment 34, the type wheel I1 will have reached its zero or starting position with the' blank portion on the periphery of the type wheel presented to the printing point,

Segment 34', as previously described, is yieldably connected to shaft I 6 by means of coil spring 32, The purpose of this is toprevent segment 34 during the character'selection operation, from binding against'the lateral portion 18; .that is, assuming that segment 34 during character selection is presented with its forward edge lill just to the right 'of the Vertical path of portion 18, the lever 41 in response to a selecting impulse will be actuated in a clockwise manner, thus bringing portion 18 downwardly into the path of edge |01. Then on itsv upward movement, lever 41 will actuate ratchet wheel 28 to cause its counterclockwise rotation. However, before ratchet wheel 28 has advanced very far, edge lill will iinpinge against portion 18 which has not yet escaped the segment 34. Without the yieldable spring connection between segment 34 and shaft I6, .the pressure of pawl 46 against ratchet wheel 28 by means of spring 54 would cause segment 34 to bind against portionv 1.8,k thus lpossibly injuring the mechanism. To compensate for this, segment 34 is permitted to yield and pawl 46 is permit-ted to complete its action upon ratchet wheel 28, whereafter when portion 18 clears the segment 34, segment 34 will be biased by spring 32 to its normal counterclockwise position.

First modification f lfn` Fig. 5 is shown a modified Aform of the invention wherein the main features' of difference from the preferred form are the substitution for a print-ing magnet having two windings, of ar printing magnet having a single winding' of marginal character,` and a blocking magnetv comparable in effect to the second mentionedwinding of the magnet 55 shown in Fig. 2. Furthermore,v instead V'of having pins mounted on the ratchet wheel which controls the single character space movement of the type wheel, a star wheel is provided to cooperate with a. blocking arm controlledA by the blocking magnet.

The printer shown in Fig. 5 comprises a base plate |02 upon which is supported, in a manner Similar to that shown in Fig. 1, a mounting plate |03. Journaled in themounting plate |83V is one end of a shaft |04, lthe other end of which is yJ''flrrlffbled bracket (not Sharm) .but sim;- ilar".to'bra"`kt'l5 f Fig. 2'.r Carrledionshaft i074,

aaaecr in 'a manner similar to that shown in Fig. 3, are a `type wheel and a pinion (not shown but comparable to type wheel I1 and pinion 2| in Fig. 3), a ratchet wheel |05, and a segment |06. Ratchet wheel |05 is provided with a sleeve portion on which is carried la ratchet wheel |01 comparable to ratchet wheel 28 of Fig. 3. y

Ratchet wheel |05 carries a pair of planetary gears, only one gear |08 of which is shown in Fig. 5. Gear |08 meshes with a gear |09 comparable to pinion gear 2| shown in Fig. 3. Ratchet wheel |01 has associated integrally therewith a gear comparable to gear 26 of Fig. 3, which meshes with a planetary gear (not shown) companion to planetary gear I 08.

Cooperating with ratchet Wheel |05 is a pawl pivotally carried on the end of :a pawl operating lever ||2. Pawl is normally held into engagement with ratchet wheel |05 by a compression spring II3. Lever ||2 is carried by the armature |I4 of an electromagnet II5, which is supported on a bracket I I6 carried on the mounting plate |03. Armature ||4 is pivoted at ||1 to bracket ||6. Lever 2 is biased in a clockwise direction by a spring ||8 and is guided in its oscillatory path by a guide |20.

Ratchet wheel |01 cooperates with a pawl ||9 pivotally carried on the end of a pawloperating lever |2I. Pawl ||9 is biased into engagement with ratchet wheel |01 by a spring |22. Lever |2| is carried by the armature |23 of an electromagnet |24 which in turn is supported on a bracket |25 fixed to the mounting plate: |03.

Armature |23 is pivotally mounted at |26 toH bracket |25. Lever 2| is biased in a counterclockwise direction by a spring |21 and is guided Ain its oscillatory path by -a bracket |28. Lever |2| is also provided with a vertically extending arm |29 which terminates in a laterally disposed portion |3| adapted to cooperate with the segment |06. Carried on a bracket |32 fixed to the mounting plate |03 is a printing magnet |33, the armature |34 of `which is pivoted at |35 to bracket |32. A printing lever |36 is fixed to the armature |34 and is'biased in its clockwise direction by a spring |31. Lever |36 carries .at its right end an upstanding lever |38 which controls a printing platen not shown. Lever |36 also carries adjacent its right end a spacing pawl |39 which is maintained by a spring I 4| against a spacing ratchet wheel |42 carried on a shaft |43 journaled in the mounting plate |03, Shaft |43 carries at its opposite end (on the reverse side of plate |03) a friction roller (not shown) comparable to roller 89 in Fig, 1 which cooperates with a pressure roller to effect thespacing movement of the tape. Spacing ratchet |42 is also provided with a spring biased detent |44'.

Ratchet wheel |05 instead of beingprovided with stopV pins, similar to pins 16 shown in Fig.

2, has flxedly related thereto a starjwheel |45 which cooperates` with a blocking arm |46 fixed to the armature |41 of a blocking magnet |48. Armature |41 ispivoted at |49 to a bracket I 5| which also carries the magnet |48 and isl mounted on the base plate |02. A spring |52r biases the armature |41 and blocking lever |46 in` a counterclockwise direction to hold the laterally dis-v posed end |53 of lever |46 normally out of engagement with star wheel |45; As set forthA hereinoefore, printing magnet |33 and blocking magnet |48 of the form of invention shown in Fig. 5 are comparable in vfunction to magnet 55 shown in Fig. 2 in that the latter magnet combines the printing winding and the blocking winding, whereas in'Fig. 5 these windings are embodied in separate magnets.

In operation, the form of the invention shown in Fig. 5 is substantially the same as that shown in Figs. 1 to 3. Upon receipt of character impulses 83 over the iirst line wire, magnet I5 connected therein becomes energized intermittently in response thereto to effect the oscillation of lever ||2 which, through pawl III, causes the rotation of ratchet wheel |05 in a clockwise direction a number of angular steps (one for each tooth) equivalent to the number of character impulses received on said first line wire. This counterclockwise movement of` ratchet |05 causes throughplanetary gear |08 the counterclockwise movement of gear |09 because pawl ||9 is holding ratchet wheel |01 againstl movement. This counterclockwise movement of gear |09 is transferred to shaft |05 to cause the movement of th type wheel one character space.

Likewise, the reception of character impulses 84 over the second line wire energizes magnet |24, connected therein, intermittently to impart oscillatory movement to lever I2| which, through pawl I9, rotates ratchet wheel |01 in a counterclockwise direction one tooth distance for each impulse received over the second line wire. This movement of ratchet wheel |01 is. imparted to shaft |04, in a manner similar to that shown since the type wheel and other mechanism on l shaft |04 are at this time quiescent. Thereafter a series of restoration impulses 85 and 86 are received over both line wires concurrently but in a staggered manner, as indicated in Fig. 4, the effect of which is to operate magnets ||5 and |24 alternately and to energize the blocking magnet |48 continuously. Due to the marginal character of printing magnet |33 it will not become ener'- gized by the restoration impulses since it requires a stronger current than that carried by the restoration impulses to effect its energization. -As magnet ||5 operates, it effects, through lever ||2 and pawl III, the counterclockwise rotation of ratchet wheel |05 and star wheel |45. Since blocking magnet |48 is now energized, arm |46 will present its end |53 into the path of star wheel |45, thus permitting star wheel |45 to be rotated until one of its arms impinges against end |53, the remaining restoration impulses on the first line wire, if any, having no effect on the ratchet whee1 |05. Similarly, the restoration impulses received over the second line wire will operate the magnet |24 to rotate ratchet Wheel |01 (and hence shaft |04 and segment |06) until segment |06 is presented beneath portion |3| of arm |29, whereafter further oscillation of lever IZI is prevented. In thiscondition, the typel wheel is brought to its starting or zero position with the segment |06 just clear of the .p0rtion |3|. This latter condition is attainedv due to the fact that after the lastrestoration impulse has been received and discharged, the magnets H5, |23, and |48 become deenergized and springs ||8 and |21 are eiective to return their respective levers ||2 and |2'| totheir spring biased positions, thus bringing segment |06 clear of the portion |3| in readiness for a subsequent selection.

Second modification The form of the invention shown in Figs. 6 and 7 is substantially the same as the form shownl in Fig. 5 with the exception that the restoration of the type wheel to its zero or starting position is eiected mechanically insead of electromagnetically through the instrumentality vof restoration impulses; that is, with this form of the invention, the signals received over each line wire are thev same as shown in Fig. 4 with the elimination of portion 82 comprising the restoration impulses. In this form of printer the star Wheel |45, segment |06, extension |29, blocking lever |46, and magnet |48 of Fig. 5 are eliminated and in their stead a clutch mechanism, generallyindicated |54` in Fig. 7, is substituted. Having reference to Fig. 6, shaft |55 is comparable to4 shaft |04 in Fig. 5; ratchet wheel |56 is comparable toratchet wheel |05; and ratchet Wheel |51 is'comparable to ratchet wheel |01. Associated with ratchet'whee-l |56 is a pawl operatingv lever |58 comparable to lever ||r2, and associated with ratchet wheel |51 is a pawl operating lever |59 comparable' to lever |2|. Also, a'printing Vlever |6| is providedl which is comparable to lever |36 in Fig. 5. Now, upon receipt of the signal impulses 83 and 84 the magnets (not shown) `controlling the levers |58 and |59 are energized alternately to effect the positionment 'of thetype Wheel for character printing, after which the prolonged printing impulse is received over each line wire simultaneously to operate a printing magnetinot shown) comparable to magnet |33 in Fig. 5.

The printing magnet of the printer shown in Figs. 6 and '7, in addition to effecting the printing operation, acts upon the aforementioned clutch rnecll'ianisrnV |54 to permit the restoration of the type wheel to its Zero or starting position after printing. The driving portion |62 of the clutch has a slidable connection with gear |63, which gear is comparable to gear |09 of Fig. 5. Driving portion" |62 is normally urged into meshing engagement with driven portion |64 by a compression spring |65, so that, as the gear |63 rotates, it will impart similar rotation to the driven portion |64. The driven portiton |64 is integral with a sleeve |66 which is xed to the shaft |55. Integral with sleeve |66 is a spiral pulley |61 anda stop arm |68; thus, as gear |63 rotates response to the character positioning operation of the type wheel, it imparts through the clutch portion |62 like rotation, through the driven portion |64, to sleeve |66. As the type wheel is being rotated during the character selecting operation, the arm |68 and pulley |61will be .rotated in a counterclockwise manner, the pulley as it rotates tending to stretch a return spring |69 which is connected to said pulley by a cord which is directed around an idler pulley |12.

After the type wheel has been positioned in response to the selecting impulses, and the prolonged printing impulse has been received to actuate the printing magnet, the printing lever 6 will `be actuated in an upward direction Vas viewed in Figs. 6 and 7 against the action of a spring |13 effect, through link |14 and platen memberl15, the printing'operation. Substantially simultaneously therewith, the printing 1e- Ver |i6,| acts through an extension |16 thereon to rotate a bell crank lever |11 (pivotally mounted at`|18 to a bracket |19 supported on base plate |02) in a counterclockwise direction (as viewed in Fig. 7). Bell crank |11 acts upc-n a depending armll offa clutch release lever |82 to rotate said leverr l |82 in a'clockwise direction about its pivot shaft |83 to cause arm |84 of said lever |82 to disengage the driving portion |62 of clutch mechanism"|54 from the driven portion |64. Due to the fact that a stabber portion |80 on platen member |15 cooperates with a star Wheel (not shown, but comparable to star Wheel |8 in Fig. 1)v during the printing operation, the sleeve |66 is not, at this time, -free to rotate `under the pull of spring |69. However, after printing is completed, stabber |80 is. withdrawn from the star wheel and sleeve |66 is free to be rotated under the actidn of spring |69 in a clockwise direction until stop arm |68 strikes against a xed stop To insure the disengagement of portions |62 and |64 of clutch mechanism |54 for a sufficient period of time to enable the complete return of stop arm |68 tothe stop |85, a latch member |86 is provided which cooperates with a vertical arm |81 on clutch release lever |82. Thus, when the CIK clutch release lever |82 is actuated in a clockwise directionV to effect the disengagement of portion |62 from |64, arm |81 is also actuated in a clockwise directionso as to 4become latched by the stepped portion of latch |86, due to the action of spring |88. Then -just before stop arm |68 reaches its stop |85, it strikes a projection |89 on latch |86 to rotate latch |86 slightly in a clockwise direction against the action of its spring |88 to release said latch |86 from arm |81, thereby permitting compression spring |65 to effeet the reengagement of clutch portions |62 and |64.

Third modification In Figs. 8 to 12 inclusive is illustrated a form of the"invention embodying rotary-armature type magnetsy to effect the character positioning of thety'pe wheel. According to this form of the invention, rotary-armature type magnets are substituted for the neutral magnets of the previously described forms of the invention. The printer of the'form shown in Figs.'8 to 11 comprises a' base plate 20| from which portions 202 (in the' present'instance two in number) have been struck to provide securing means for a vertical p l'ate 203 '(Figs. 9 and 10). Plate 203 provides a support Vfor a short shaft 204 which rests in a bushing'zosheid inpiate 203 by a nut 20s.

baseyplate 20|.

Fixed to shaft 204 is a-type wheel 2H, a star wheel 2| 2, and a sleeve member 2|3 having formed integrally thereon a spur gear 2|4 and a camv portion 2|5. Meshed With gear 2|4 is a planetary 'gear 2 I6 fixed to `a stub shaft 2| 1 loosely journaled at the'extremity of an arm 2|8 xed to tnt-...start 201. Also exec to the Stub shaft 2|1 is a companion planetary gear 2| 9 which meshes with a pinion gear 22| pinned to a sleeve member 222. Sleeve member 222 is loosely mounted on shaft 201 and carries fixedly thereon a rotary-armature 223, Figs. 8 and 9. Integral with sleeve 222 vis a multiple-toothed cam member 224 having cam teeth equal in number to the number of poles on the rotary-armature 223. Cooperating with cam member l224 (as viewed in Fig. 8) is a follower roller 225 carried at the extremity of a lever 226 pivoted at 221 to the mounting plate 208. Lever 226 is biased in a counterclockwise direction to hold roller 225 against cam 224 by a spring 228. The cam teeth on the multi-toothed cam 224 are so conformed or shaped as to assist the rotary-armature magnet 229 in rotating the armature 223 in a manner to be presently described.

Armature 223 is rotatable between arcuate core pole faces 286, the curvature of which is generated on a constant radius from the axis of rotation of armature 223 as a center. of armature 223 are curved in conformity with a spiral generated from the axis of rotation of ar,- mature 223 by uniform increase in radii between the leading and trailing edges of a pole face 285. It may be added that the spirally conformed surfaces of all of the pole faces 285 are identical, the radii at the leading edges of all being equal, the radii at the trailing edges of all being equal, and the variation in radii from maximum to minimum being uniform for al1 of the pole faces. Thus, the leading edges of all the armature pole faces pass the core pole faces 286 at a predetermined distance 289 therefrom so as to provide a gap therebetween, and the trailing edges pass the core pole faces at a lesser distance 29| therefrom, so that the gap is continuously diminished as an armature pole face passes into and out of range with a core pole face `286. The armature 223 is revolved by means of the attraction exerted by the poles 23| and 232 of magnet 229. The curvature of faces 285 is such that as the arma.- ture-poles advance within the field of the magnet poles 23| and 232, the separation of the arcuate faces 285 from the pole faces 286 diminishes. The position of strongest attraction, therefore, is opposite those portions of edges 285 last to reach the pole faces 286, and the armature 223 tends to stop in such position. Thus, upon energize-tion of magnet 229, a magnetic path will be set up between poles 23| and 232 such that the rotaryarmature will be rotated initially (in a clockwise direction as viewed in Fig. 8) an amount sufficient to raise the follower roller 225 to the high point on the tooth of the multi-toothed `cam 224,

after which spring 228 acts lthrough lever 226 andfollower roller 225 to urge the cam 224 and rotary-armature 223 an additional angular amount. Accordingly, armature 223 is revolved by means of the alternate action thereon by poles.23|232, and cam means 224, 225, 226, 228.

Also carried on sleeve 222 is an arm 233 (Figs. 9 and 11) which is fixedly carried upon sleeve 222 by being clamped against the rotary-armature 223 by a nut 234. The function of arm 233 in the restoration operation will presently appear. Fixed to the shaft 201 is a sleeve 235 which is provided integral therewith with a multi-toothed cam 236. A rotary-armature 231 is carried on sleeve 235 asis also a star wheel 238, both of which are xed to the sleeve 235 by the clamping action of a nut 239. As previously indicated, shaft 201 is journaled in the bracket 203 and Pole faces 285 y to afford a broader bearing at this point, a ring portion 24| is Aprovided which is secured to the bracket 209.

The rotary-armature 231 is associated with the poles 242 and 243 of electromagnet 244. A detent roller (not shown) is also provided to cooperate with the multi-toothed cam 236 in the same manner that follower roller 225 cooperates with cam 224. The action of electromagnet 244 upon its armature 231 in response to each energizing impulse is the same as previously described in connection with magnet 229 and armature 223.

Stop arm 233 cooperates with an extension 245 (Fig. 11) integral with an armature member 246 pivoted at 241 to a bracket 248. The armature 246 is so designed as to span pole faces 23| and 242 so that it acts in response to both magnets 228 and 244. Armature 248 is biased to its countereclockwise position against an adjustable stop 249 by a spring 25|. Star wheel 238 cooperates with a stop lever 252 which is fixed to a rock shaft 253 mounted in brackets 248 and 288. Fixed to the o-pposite end of shaft 253 (as viewed in Fig. 8) is a cam follower arm 254 which is biased in a counterclockwise direction against the cam 215 by a spring 255. A detent spring 256 (Fig. 1l) cooperates with armature 231 to prevent back slip. A similar spring (not shown) is also provided for armature 223.

As shown in Fig. l0, there is mounted on base plate 20| an electromagnet 251 which controls the printing operation and which is also -provided with a rotary-armature 258 similar in design to armature 231. Armature 258 is fixed to a sleeve 259, which in turn is pinned to a shaft 28| journaled in the bracket 208, and also in a bracket 252 mounted on base plate 20|. Fixed to shaft 26| is a sleeve member 283 which has integral vtherewith a gear portion 254 and a multi-toothed cam portion 285. Gear 264 meshes with a gear 266 (Fig. 8) mounted on a stub shaft 251 carried in plate 203. Shaft 251 controls the character spacing of the tape by being provided with a spacing roller (not shown) in a manner similar to roller 89 in Fig. l.

Cam 265 cooperates with a follower roller 258 carried at one end of a lever 269 fixed to a short shaft 21|. Lever 259 is biased in a counterclockwise direction (as Viewed in Fig. 8) by a spring 212 to hold follower roller 268 against cam 255. Shaft 21| is suitably supported in a bearing 213 (Fig. l0) carried in plate 223 and has fixed to its outer end a, printing arm 214 which cooperates with a platen 215 pivoted at 218.

Mounted above arm 228 (Fig. 8) is a Contact assembly 211, in which contact 218 is normally closed and contact 219 is normally opened. Lever 226 acts through insulated stud 28| to control the contact assembly 211. y

In Fig. 12 is shown diagrammatically the electrical circuit for operating the magnets 229,' 244, and 251. Magnet 229 is connected to line wire 282 which will hereinafter be designated as the rst line wire. The second line wire 283 is con nected to terminal 284 (Figs. 8 and 12) of the contact assembly 211 and normally completes a circuit for character selecting impulses over wire 283, terminal 284, contact 218, magnet 244 to ground. The impulses `over the first line wire are directed over conductor 282 through magnet 229, thence to ground. The purpose of contact assembly 211 is to disassociate the printing magnet 251 from the line wire 283 during the reception of chiaracter' selecting and restoration impulses since otherwise magnet 251 would have al tendency to operate prematurely.

Upon reception of the character selecting impulses which are of the nature of impulses 83 and 64 shown in Fig. 4, magnets 223 and 244 will be energized alternately. In response to each selecting impulse over wire 232, magnet 225 will be energized momentarily to cause its rotary-armature 223 to be attracted to cause the surfaces 285 of oppositely disposed arms thereof to register opposite the faces 266 of poles 23! and 232. This magnetic attraction imparts a predetermined amount of rotation to armature 223, which amount is sufcient to cause follower roller 225 to ride up on the high part oi a tooth of the cam 224 whereafter, upon deenergization of magnet 226, spring 223 acts to rotate cam y224 a predetermined additional distance to the bottorn of the slope of said cam tooth. It is thus seen that the armature 223 is rotated in part by the magnet 223 and in part by the spring 228 cooperating with the multi-toothed cam 224.

This movement imparted to rotary-armature 223 is transmitted through gear 22| to planetary gears 213 and 2|6 which, through gear 2M and shaft 254, causes the type wheel 2H to rotate a single character step. It is understood that the proportions of the gears 2H, 2|9, 216, and 2|4, are chosen to properly translate the movement of armature 223 to the type wheel 2| l. It should be noted that when lever 226 is rocked upwardly by the cam 224, contact 213 will be opened momentarily and the contact 213 will be closed.

When a character signal impulse is received over the second line wire 233, it eiects the energization of magnet 244 which, when energized, causes armature 23'!A to rotate until the points of opposite poles register opposite the pole faces 242 and 2113, the action being the same as described in connection with armature 223. During this initial rotation, the cam follower roller (not shown) associated with cam 236 will ride onto the high part of a cam tooth preparatory to imparting additional rotation to said cam at the termination of the signal impulse. manner, shaft 201 is rotated to impart, through arm 2|8, movement to -planetary gears Zll and 216 and gear 214 to rotate type wheel 2li six character positions. It is thus seen that character selecting impulses which are received over line wires 282 and 233 in varying combinations result in the corresponding rotation of type wheel 2| to eiect the proper positionment thereof in accordance with the character selected.

After the character impulses 82 and 63 have been received, a prolonged printing impulse 8| is received simultaneously over wires 282 and 233. The effect of the printing impulse on magnet 223 will be to hold the rotary-armature opposite the pole faces 286, thereby maintaining the follower roller 225 at the apex of a tooth on the multi-toothed cam 224. In this position the contacts 219 are closed and the contacts 218 opened so that the printing impulse received over wire 283 (which is slightly retarded to insure the prior closing of contact 219) is transmitted through terminal 264 and contacts 219 through printing magnet 251 to ground. The effect of this energization of magnet 251 will be to rotate the rotary-armature 258 initially to cause follower roller 263 to ride onto the apex of a tooth on the multi-toothed cam 265. This action of cam 265 upon follower roller 26B causes lever 269 to rotate in a clockwise direction about pivot In this shaft 21|.,l which rotation imparted through shaft 21| to printing arm 214 and thence to the platen 215, thereby throwing the platen 215 against the type wheel 2|| to effect printing of the selected character. Lever arm 214 is provided with a knife-edge 281 which during the printing operation cooperates with the star wheel 212 to hold the type wheel 2 fixed during the printing function.

Following the receipt of the printing impulse,

the restoration impulses 85 and 86 are received,v

and their action upon the restoration mechanism is similar in principle to that described in the previous forms of the invention. Since the restoration impulses are received alternately over line wires 282 and 283, the alternate energizations of magnets 229 and 244 cause substantially continuous attraction of common armature 246 to bring extension 245 into the path of stop arm Stop arm 233 being controlled by the onestep armature 223 will be rotated until it is arrested by extension 245.

The restoration impulses received over line wire 203 will energize the six-step magnet 244 to cause rotation of the type wheel 2II in the manner previously described. However, when the high part of cam 2|5 cooperates with a follower arm 25,4, stop arm. 252 will be rotated into.

the path of the arms of star wheel 238 so that after this occurs, further restoration impulses will be inellective to rotate armature 231. When this condition exists whereby stop arm 233 is arrested by extension 245 and star wheel 238 is arrested by lever 252, the type wheel is so positioned that the initial or starting position is one-step or character space removed from the actual zero point, so that upon deenergization of magnets 229 and 244, stop arms 245 and 252 will be removed from their stopping position thus permitting the follower rollers to act upon their respective cams 224 and 236 to impart nal rotation to type wheel 2| l, thus bringing type wheel 21| into its actual starting or zero position.

Transmittz'ng mechanism In Figs. 13 to 19 inclusive are shown various forms of transmitters and circuits therefor which may be employed in connection with the receiving printers according to the invention. In Figs. 13 to 15 inclusive is illustrated a keyboard transmitter of the' type shown land disclosed in United States Patent No. 1,595,472. As shown in Figs. 13 and 14 the keyboard portion, indicated generally as 30|, is provided with a set of keys 302 arranged similarly to the well-known` typewriter keyboard, and, as illustrated in Fig. 13, key levers 303 associated with the keys 362 are pivotally mounted on a common shaft 304 and are spring held in normal horizontal position by individual springs (not shown). Arranged transversely below the key levers 303 (Fig. 14), in operative relation thereto, are a series of V-notched selector bars 305 which are adapted to be operated permutably, in wellknown'manner, in accordance with the key depressed.

The selector bars 305 are pivotally articulated to a corresponding series of locking latches 306 which are adapted to be rocked to either of two positions thereby. Associated with latches 306 is a corresponding series of contact levers 301 for making. and v.breaking contacts 308. Contact levers 301 cooperate with individual contact cams 303 mounted on shaft 3| The shaft 3| is provided with a single revolution clutch mechanism (not shown) which is controlled by a universal bar member as set forth in Patent No. 1,595,472.

The operation of the transmitting unit consists essentially in the depression of a key lever 303 which effects the arrangement of the set of selector bars 305 periodically in accordance with a predetermined code combination, the setting of which determines the position of the locking latches 306. The rotation of the cams 309 is initiated substantially simultaneously with the setting of the locking latches 306, and a locking loop 3|2 controlled by a cam 3|3 is permitted to rotate in a counterclockwise direction Y(Fig. 14) to effect the locking of latches 306-. The setting of the locking latches 306 determines whether the contact levers 301 shall or shall not be affected by their associated cams 369 to cause the opening or closing of their associated contacts 308 to transmit over a signal line (as will appear presently from a description of Fig. 16) to the receiving station a predetermined combination of signalling impulses. The respective notches in the cams 303 are arranged in a spiral progression so that upon the rotation of the cam assembly, the contacts 368 Will be controlled successively.

In the present form of transmitter, the contact cams 309 are eight in number and are divided in groups of four each, each group of four being connected to a separate line wire over a two wire telegraph system. In Fig. 15 is shown the series of eight contact cams 369 with their respective contact levers and contacts. In this illustration, contact cams 32|, 322, 323, and l324 comprise one group, the contacts 308 of which are connected over line wire 3|4 of Fig. 16, and contact cams 33|, 332, 333, and 334 comprise a second group, the contacts 308 of which are connected over asecond line wire 3|5 of Fig. 16. It will be noted that contact cams 32| and 33| are provided with a single depression in response to which a single impulse is transmitted through a contact 3084 for each` revolution of the cam. It will be noted further that cams 322 and 323 and cams 332 and 333 are each provided with two adjacent notches so that for each revolution of these cams, two impulses will be transmitted. Then to enable the sending of one to five character impulses over each wire 314 and 3|5, the cams in each group may be selected in proper combinations; yforV example, to send a single impulse over line 3|4, cam 32| only would be operated. To transmit two impulses over line 3|4, cam 322 or cam 323 will be operated. To send three impulses over line 3| 4, cam 32| would be operated simultaneously with cam 322 or 323. To send four impulses over line 3|4, cams'322 and 323 would be operated simultaneously, and to transmit ve signals over the line all of the cams 32|, 322, and 323 would be operated simultaneously. The same permutable operation of the second group of cams 33|, 332, and 333 is effected to transmit signals over line 3| 5. It will be observed that the notches of each group of cams are arranged in a progressive manner.

Cams 324 and 334 are not controlled by lock latches 303 and are permitted to rotate invariably for every operation of transmitting shaft 3| Each of the cams 324 and 334 is so cut as to transmit (following the character selecting impulses) rst the prolonged printing impulse and thereafter six restoration impulses.

Having reference to Fig. 16 there is shown a circuit diagram for a two Wire telegraph system employing the transmitter shown in Figs. 13 to l5 and printers according to Figs. 1 to 4, for example, herein described. According to this system, impulses in accordance with the diagram shown in Fig. 4 are transmitted from battery 335, through contacts 308, over line wires 3 I4 and 3|5, through their respective stepping magnets 38 and 49, thence through printing magnet 55 to ground.

In Figs'. 17 to 19 is shown a dial type of transmitter. In accordance with this form of transmitter, a series of dialing keys 35| are disposed above a casing 352, and integral with each dialing key is a key lever 353 loosely carried upon a shaft 354. Each of the key levers 353 is provided with oppositely directed arcuately shaped arms 355 and 356, the upper arcuate edges of which are notched in code manner. Associated with the arm 355 of each of the key levers 353 is a pin 351 carried on a common rod 358 suitably journaled in the casing 352. There is also carried on the rod 358 a contact operating pin 359 which cooperates with the upper blade 36| of contact 362. The assembly comprising rod 358 and pins 351 and 359are biased in their clockwise direction (as viewed in Fig. 17) by a spring 363. When a key lever 353 is rotated in a counterclockwise direction, the code projections on the arm 355 rook the rod 358 repeatedly in a clockwise direction and rotate arm 359 away from the contact 36|. Then, upon the return of key lever 353 to its rightward or clockwise position (as shown in Fig. 17) the code projections on arm 355 will again rock rod, 358 repeatedly in a counterclockwise direction against the action of spring 363 to close the contact 362 intermittently to transmit impulses over the line Wire, as will be hereinafter explained.

Similarly there is associated with the arm 356 of each of the key levers 353 a pin 364 which is carried upon a common rod 365. There is also fixed to rod 365 a contact operating pin 366 which operates a contact 361. As a key lever is rotated counterclockwise, the code projections upon arm 356 act, through pins 364, to rock rod 365 re peatedly in a clockwise direction and rotate arm 366 away from contact 361. Then, upon return of the key lever 363 to its clockwise position, the code notches on arm 356 act to rock rod 365 repeatedly in a counterclockwise direction against the action of its spring 368 to close conta-ct 361 intermittently to transmit signal impulses over a second line wire.

According to the presently described form of the invention, means is provided for preventing the operation of more than one key lever 353 at a time; that is, when one key lever 353 is operated, all of the-remaining key levers are locked against operation. To achieve this result, an armv 369 is associated with each key lever which arms 369 are xed to the shaft 354. Pivotally carried on key lever 353 adjacent the outer extremity of arm 369 is a bell crank lever 31|. There is also carried on key lever 363 a bell crank lever 312, and bell cranks 31| and 312 are biased attrahent- 1y by a common spring 313. Extending longitudinally through the casing 352 and supported therein is a rod 314 which cooperates with bell cranks. 31| and 312. Also xed to the shaft 354 is an arm 315 to the extremity of whichris connected one end of a spring 316, the other of which is anchored to the `casing 352. Thus, in this manner, all of the arms 369 are biased to their clockwise position against a stop 311 carried on each of the key levers 353.

When the arms369 assume their clockwise position against stops 311, their -ends318 lthereof also bear against bell cranks 312 to rotate the lata ter sufficiently to remain disengaged from bar 374 as indicated in Fig. 17. Also when key lever 363 is held in its clockwise position, bell crank lever 377 bears against bar 374 in such a manner as to maintain its horizontal arm disengaged from end 378 of arm 369.

Now, when a key lever 353 is operated by means of its associated dialing key 35|, and is thereupon actuated in a counterclockwise direction, its pin 377 engages arm 369 and carries said arm forwardly therewith. This action is rendered possible because arm 369 is still bearing against bell crank 372 to hold said bell crank disengaged from bar 374, and as lever 353 is moved counterclockwise, bell crank 372 passes under the bar 374. Since all of the arms 359 arei'lxed to shaft 354, the remaining arms 369 will be moved independently of their lassociated key levers 353. Then, because of this operation of arm 359 independently of key levers 353, bell cranks 372 of all but the operated key lever 353 will be free to be actuated by their respective springs 373, so as to bring the horizontal arms of bell cranks 372 into latching engagement with bar 374. Therefore, so long as arms 369 of all but the operated key lever 353 remain out of contact with their respective bell cranks 372, all of the remaining key levers 353 are locked against operation. In Fig. 18 is shown a plan View of the dial transmitter with a part broken away tov show the contact 362.

In Fig. 19 is shown a circuit diagram. of a two wire telegraph system employing the dial transmitter shown in Figs. 17 and 18. In this system the contact 362 is operated intermittently in accordance with the code notches on the arm. 355 of a key lever 353 to transmit impulses over the first line wire 379 through a stepping magnet 38| and print magnet 382 to ground. Similarly, contact 367 is operated intermittently in response to the code notches on the arm 355 of a key lever 353 to transmit over a second line wire 383 signal impulses to a stepping magnet 384 thence through the print magnet 382 to ground. Since print magnet 382 `is of marginal operation, it will not respond to impulses received over either line wire singly but only when a printing impulse is received over both line wires 379 and 383 simultaneously. It is understood that the code notches on arms 355 and 356 may comprise the character signaling impulses, the printing impulse, and restoration impulses in accordance with the signal indicated in Fig. 4, or in the event that a printer such as shown in Figs. 6 and 7 is employed, the restoration impulses will be omitted; the restoration of the type wheel being effected, it will be recalled, in response to the printing impulse, by a spring return means.

Although the present invention has been disclosed in connection with certain specic embodiments thereof, it is understood that such embodiments are merely illustrative and not restrictive, and that all forms coming within the scope of equivalency of the appended claims are intended to be covered by the invention.

What is claimed is:

1. In a printing telegraph receiver, a dually controlled type Wheel, electromagnetic means responsive to signal impulses for controlling vthe movement of said type wheel, and planetary gearing interposed between said type Wheel and said means for eiectuating said control.

2. In a printing telegraph receiver, a dually controlled type wheel, combination rotary-armature and mechanical means responsive to signal impulses for controlling the movement of saidv y type wheel, and planetary gearing interposed between said type Wheel and said combination means for eiectuatingsaid control..

3. In a printing' telegraph receiver, a dually controlled type Wheel, unidirectional rotary-armature means responsive to signal impulses to initiate each step-by-step movement of said type wheel, and spring and cam means effective supplementally to consummate each vsaid movement.

4. In combination in a printing telegraph receiver, a dually controlled type wheel, a rst rotary-armature means responsive to signal `impulses for controlling the movement of said type wheel in one manner, a second rotary-armature means responsive to signal impulses for controlling the movement of said type wheel in another manner, a third rotary-armature means for controlling the printing of the selected character, and means effective only when said first cidental printing impulsesl to effect printing of the selected character.

6. In a telegraph system, two channels of transmission, a transmitting means comprising two groupsof transmitting elements, one group for each channel, means whereby said elements are operative in a single cycle to impress initially character selecting impulses over each channel in staggered manner, followed by a printing impulse occurring coincidentally on each channel, and receiving apparatus comprising a dually controlled character carrying means, a rst electromagnetic means responsive to the character selecting impulses over one vof said channels for controlling the movement of said character carrying means in'one manner, a second electromagnetic means responsive to the character selecting impulses over the other vof said channels for controlling the movement of said character carrying means in another manner, and a third electromagnetic means common to both channels responsive tosaid coincidental printing impulses for controlling the printing of the selected character.

7. In a recorder, a dually controlled recording means, means responsive to signal impulses for controlling the operation of said urecording means, and planetary gearinginterposed between saidrecording means and said controlling means for effectuating said control.

8. In a recorder, a dually controlled recording means, electromagnetic means responsive to signal impulses for Vcontrolling the operation of said recording means, and planetary gearing interposed between said recording means and said electromagnetic means for effectuating said ccntrol.

9. In a recorder, a dually controlled recording means, combination rotary-armature andl mechanical means responsive to signal impulses for controlling the movement 4of said recording 'lilI means, and planetary gearing interposed between said recording means and said combination means for efectuating said control.

10. In a recorder, a dually controlled rrecording m e a n s, unidirectional rotary-armature means responsive to signal impulses to initiate each step-by-step movement of said recording means, and spring and cam means effective supplementally to consummate each said movement.

11. In combination in a printing telegraph receiver, a dually controlled type wheel, a first electromagnetic means responsive to signal impulses for controlling the movement of said type Wheel in one manner, a second electromagnetic means responsive to signal impulses for controlling the movement of said type wheel in another manner, a third electromagnetic means for Controlling the printing of the selected character, and means associated with each electromagnetic means cooperating to control the restoration of said type Wheel to its zero position prior to each character selection.

12. In combination in a printing telegraph receiver, a dually controlled recording instrumentality, a rst means responsive to signal impulses for controlling the movement of said recording instrumentality in one manner, a second means responsive to signal impulses for controlling the movement of said recording instrumentality in another manner, a third means for co-ntrolling recording operations, and means associated with each of said rst, second, and third means acting conjointly to control the restoration of said recording instrumentality to its zero position prior to each character selection.

13. In a printing telegraph receiver, recording means, means responsive to signal impulses for controlling the movement of said recording means, return means for said recording means, clutch means interconnecting said return means and said recording means, means to operate said recording means to effect recordations, and means actuated by said last recited means to control, through said clutch means, the operation of said return means.

14. In a recorder, recording means, means for controlling the movement of said recording means, spring-return means for said recording means, clutch means associated with said return means and said recording means, means to operate said recording means to effect recordations, and means actuated by said last recited means to control, through said clutch means, the operation of said spring-return means.

15. In a telegraph system, two channels of transmission, a transmitter comprising a series of keys, a permutation code selector mechanism, and two groups of contact controlling cams, one group for each channel, means whereby said cams are controlled permutably by said selector mechanism and operative in a single cycle to impress initially character selecting impulses over each channel in staggered manner, followed invariably by a printing impulse occurring coincidentally on each channel and subsequently a denite series of restoration impulses occurring on each channel in staggered manner, and receiving apparatus comprising characten selecting means responsive to said rst recited staggered impulses to effect the character selection in variable steps in accordance with the variable number of impulses applied to each signal channel, recording means common to both channels responsive to said coincidental printing impulses to eiect printing of the selected character, and restoration means responsive to said restoration impulses to restore said character selecting means to zero position.

161. In a telegraph system, two channels of transmission, a transmitting means comprising two groups of transmitting elements, one group for each channel, means whereby said elements are operated in a single cycle to impress initially character selecting impulses over each channel in staggered manner followed by printing impulses impressed coincidentally over said channels and subsequently restoration impulses impressed over each channel in staggered manner, and receiving apparatus comprising a character carrying instrumentality having a normal position, character selecting means in each channel responsive to said initially impressed character selecting impulses to control said instrumentality, a recording means common to both channels responsive to said coincidental printing impulses to eiect printing of the selected character, and restoration means responsve to said restoration impulses to return said instrumentality to its normal position.

HOWARD L. KRUM. 

